• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.191-191
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• 2017

Floods have become more widespread and frequent among natural disasters and consisted significant losses of lives and properties worldwide. Flood's impacts are threatening socio-economic and people's lives in the Mekong River Basin every year. The objective of this study is to identify the flood hazard areas and inundation depth in the Mekong River Basin. A rainfall-runoff and flood inundation model is necessary to enhance understanding of characteristic of flooding. Rainfall-Runoff-Inundation (RRI) model, a two-dimensional model capable of simulating rainfall-runoff and flood inundation simultaneously, was applied in this study. HydoSHEDS Topographical data, APPRODITE precipitation, MODIS land use, and river cross section were used as input data for the simulation. The Shuffled Complex Evolution (SCE-UA) global optimization method was integrated with RRI model to calibrate the sensitive parameters. In the present study, we selected flood event in 2000 which was considered as 50-year return period flood in term of discharge volume of 500 km3. The simulated results were compared with observed discharge at the stations along the mainstream and inundation map produced by Dartmouth Flood Observatory and Landsat 7. The results indicated good agreement between observed and simulated discharge with NSE = 0.86 at Stung Treng Station. The model predicted inundation extent with success rate SR = 67.50% and modified success rate MSR = 74.53%. In conclusion, the RRI model was successfully used to simulate rainfall runoff and inundation processes in the large scale Mekong River Basin with a good performance. It is recommended to improve the quality of the input data in order to increase the accuracy of the simulation result.

• Speech Sciences
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• v.15 no.3
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• pp.39-51
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• 2008

Formant measurements are one of the most important factors to objectively test cross-linguistic differences among vowels produced by speakers of any given languages. However, many speech analysis softwares present erroneous estimates and some researchers use them without any verification procedures. The purposes of this paper are to examine formant measurements of complex waves which were synthesized from the average formant values of five Korean vowels using three default methods in Praat and to verify the measured values of the five vowels produced by 20 students using one of the methods. Variances along the time axis are discussed after determining absolute difference sum from the 1/3 vowel duration point. Results show that there were smaller measurement errors by the burg method. Also, greater errors were observed in the sl or lpc methods mostly caused by the inappropriate formant settings. Formant measurement deviations were greater in those vowels produced by the female students than those of the male students, which were mostly attributed to the settings for the vowels /o, u/. Formant settings can best be corrected by changing the number of formants to the number of visible dark bands on the spectrogram. Those results suggest that researchers should check the validity of the estimates from the speech analysis software. Further studies are recommended on the perception test of the original sound with the synthesized sound by the estimated formant values.

• Journal of Community Nutrition
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• v.7 no.2
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• pp.71-78
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• 2005

This study was performed to investigate dietary habits and nutrient intakes of college students in Gyeonggi-do area. Survey questionnaire and daily intake using 24-hour recall method were recorded by 351 college students (172 males, 179 females) . Nutrient intakes were calculated using Can-pro 2.0, from which $\%$RDA (Recommended dietary allowances), NAR (Nutrient adequacy ratio), MAR (Mean nutrient adequacy ratio), and ND (Nutrient density) were calculated to evaluate the quality of diets. Subjects answered 9 questions on dietary habits and these answers were calculated as 0, 0.5, and 1 point by frequency. Dietary habit was 39.57 $\pm$ 21.82 in male students and 42.12 $\pm$ 20.78 in female students out of total score of 100, showing higher score in female students. In the survey of dietary habits, the ratio of skipping breakfast 6 - 7 days a week in total subjects was $32.9\%$, showing a rather higher ratio of skipping breakfast, and the interest for balanced diet was as low as $13.2\%$ in total subjects. The importance of meals in total subjects was observed in the order of dinner ($47.6\%$), lunch ($40.2\%$), and breakfast($12.3\%$). In NAR of total subjects, nutrients with a score lower than 0.70 were calcium (0.64 $\pm$ 0.26), vitamin $B_2$ (0.66 $\pm$ 0.25), and vitamin C (0.69 $\pm$ 0.29) in ND of them, calcium (0.85 $\pm$ 0.43), zinc (0.89 $\pm$ 0.18), vitamin $B_2$(0.87 $\pm$ 0.34), and folic acid (0.91 $\pm$ 0.96) were nutrients with lower values. In the evaluation of nutrient intakes by the level of dietary habits, better scores of both NAR and ND were observed as the level of dietary habits was higher. There was a great difference in nutrient intakes in terms of $\%$RDA, suggesting the risk of nutritional imbalance. Based on the above results, it is considered that the improvement in dietary habits will contribute to the improvement of nutrition.

• Physical Therapy Korea
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• v.26 no.4
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• pp.63-69
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• 2019

Background: Both the rapid concentric and eccentric contractions during exercise repeatedly impose excessive stress on muscle tissue. The hamstring muscles are very susceptible to injury due to the tensile stress. Various interventions are currently being undertaken to prevent strain injury before exercise. Stretching is the most common method and is known to have a positive effect on flexibility and muscle performance. However, relatively few studies have investigated the potential negative factors of stretching. Objects: The purpose of this study was to examine changes in pain following the different intensity of the stretching and types of physical stress. Methods: The subjects were divided into three groups based on the intensity of stretching: 100% (S100), 75% (S75), and 50% (S50) of the measured force at the point of discomfort in static stretching and 100% (P100), 75% (P75), and 50% (P50) of the maximum voluntary isometric contraction in Proprioceptive Neuromuscular Facilitation (PNF) stretching. The pain individual subjects perceived after stretching was measured via a Visual Analog Scale (VAS) and compared between the groups Results: Despite the decrease in the intensity of static stretching, no decrease in VAS value was observed. In PNF stretching, a significant decrease was observed at P50 compared to P100. S100 was significantly higher than P75 and P50. Conclusion: Previous studies have shown that PNF has a superior or the same effect on flexibility in comparison with static stretching. This effect was maintained even in moderate intensity. PNF stretching performed under moderate rather than high intensive static stretching, which causes pain and discomfort, might be recommended in clinical settings.

• The Journal of the Korean bone and joint tumor society
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• v.2 no.1
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• pp.47-53
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• 1996

Synovial sarcoma is an uncommon malignant soft tissue tumor which usually occurs in young-aged person, and frequently involves the lower extremities. Many authors recommended wide excision, adjuvant chemotherapy and radiation therapy. The proposed factors that affect the prognosis are age, size of tumor, site of tumor in the body, depth of tumor, histologic grade and method of treatment. The purpose of the study is to analyze the factors that affect the 5-year survival rate. We retrospectively evaluated 19 cases of synovial sarcoma treated in the Kosin University Medical Center from Jan. 1982 to Dec. 1994. The overall 5-year survival rate was 47.6% and the 5-year survival rates were significantly higher(P<0.05) in the group with smaller size of mass. The significantly lower 5-year survival rates were observed in the patient with deeply located lesion and with higher histologic grade. The 5-year survival rates were higher in the patients treated with wide excision than in the patients treated with amputation. But there was no significant difference between these groups. The adjuvant chemotherapy and radiotherapy were performed. In conclusion, we suggest that the better prognosis will be observed in the patients with smaller size of tumor mass, superficially located and lower histologic grade.

• Geomechanics and Engineering
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• v.31 no.5
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• pp.505-518
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• 2022

This study introduces soil resistance multipliers at locations encompassed by the zone of influence of the helix plate to consider the added lateral resistance provided to the helical pile. The zone of influence of a helix plate is a function of its diameter and serves as a boundary condition for the modified soil resistance springs. The concept is based on implementing p-multipliers as a reduction factor for piles in group action. The application of modified p-y springs in the analysis of helical piles allows for better characterization and understanding of the lateral behavior of helical piles, which will help further the development of design methods. To execute the proposed method, a finite difference program, HPCap (Helical Pile Capacity), was developed by the authors using Matlab. The program computes the deflection, shear force, bending moment, and soil resistance of the helical pile and allows the user to freely input the value of the zone of influence and Ω (a coefficient that affects the value of the p-multiplier). Results from ten full-scale lateral load tests on helical piles embedded at depths of 3.0 m with varying shaft diameters, shaft thicknesses, and helix configurations were analyzed to determine the zone of influence and the magnitude of the p-multipliers. The analysis determined that the value of the p-multipliers is influenced by the ratio between the pile embedment length and the shaft diameter (D_p), the effective helix diameter (D_h-D_p), and the zone of influence. Furthermore, the zone of influence is recommended to be 1.75 times the helix diameter (D_h). Using the numerical analysis method presented in this study, the predicted deflections of the various helical pile cases showed good agreement with the observed field test results.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.5
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• pp.599-610
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• 2005

Purpose: The success of the bonding between electroformed gold and ceramic is dependent on the surface treatment of the pure gold coping. The purpose of this study was to evaluate the bonding strength between the electroformed gold and ceramic with varying surface treatment. Materials and methods: A total of 32 disks,8 were using conventional ceramometal alloy, 24 were using electroforming technique as recommended by manufacturer, were prepared. 24 electroformed disks were divided 3 groups according to surface treatment, i.e. 50 microns aluminium oxide sandblasting(GES-Sand), gold bonder treatment(GES-Bond) and $Rocatec^{TM}$ system(GES-Rocatec). For control group of conventional alloy 50 microns aluminium oxide treatment was done(V-Supragold). Energy dispersive x-ray analysis and scanning electron microscope image were observed. Using universal testing machine, shear bond strength and bonding failure mode at metal-porcelain interface were measured. Results and Conclusion: The following conclusions were drawn: 1. In the energy dispersive x-ray analysis, the Au was main component in electroformed gold(99.9wt%). After surface treatment, a little amount of $Al_2O_3(2.4wt%)$ were found in GES-Sand, and $SiO_2(4wt%)$ in GES-Bond. In GES-Rocatec, however, a large amount of $SiO_2(17.4wt%)$ were found. 2. In the scanning electron microscopy, similar pattern of surface irregu larities were observed in V-Supragold and GES-Sand. In GES-Bond, surface irregularities were increased and globular ceramic particles were observed. In GES-Rocatec, a large amount of silica particles attached to metal surface with increased surface irregularities were observed. 3. The mean shear bond strength values(MPa) in order were $22.9{\pm}3.7(V-Supragold),\;22.1{\pm}3.8(GES-Bond),\;20.1{\pm}2.8(GES-Rocatec)\;and\;13.0{\pm}1.4(GES-Sand)$. There was no significant difference between V-Supragold, GES-Bond, and GES-Rocatec. (P>0.05) 4. Most bonding failures modes were adhesive type in GES-Sand. However, in V-Supragold, GES-Bond and GES-Rocatec, cohesive and combination failures were commonly observed. From the result, with proper surface treatment method electroformed gold may have enough strength compare to conventional ceramometal alloy.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.7
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• pp.1241-1249
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• 2002

The extent of materials deterioration can be evaluated accurately by mechanical test such as impact test or creep test. But it is almost impossible to extract a large test specimen from in-service components. Thus material degradation evaluation by non-destructive method is earnestly required. In this paper, the material degradation for virgin and several aged materials of a Cr-Mo-V steel, which is an candidated as structural material of the turbine casing components for electric power plant, is nondestructively evaluated by reactivation polarization testing method. And, the results obtained from the test are compared with those in small punch(SP) tests recommended as a semi-nondestructive testing method using miniaturized specimen. In contrast to the aged materials up to 1,000hrs which exhibit the degradation behaviors with increased ${\Delta}[DBTT]_{SP}$, the improvement of mechanical property can be observed on the 2,000hrs and 3,000hrs aged materials. This is because of the softening of material due to the carbide precipitation, the increase of ferritic structures and the recovery of dislocation microstructure by long-time heat treatment. The reactivation rates($I_R/I_{Crit},\;Q_R/Q_{Crit}$) calculated by reactivation current densityt ($I_R$) and charge($Q_R$) in the polarization curves exhibit a good correlation with ${\Delta}[DBTT]_{SP}$ behaviors.

• Journal of Nutrition and Health
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• v.1 no.1
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• pp.9-18
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• 1968

Dividing into six(6) experimental groups; Stock Diet(SD) Group, Rice Diet(RD) Group, Rice Diet supplemented with Barley(RD-BD) Group, Barley Diet(BD) Group, Rice Diet supplemented with Millet(RD-MD) Group, and Millet Diet(MD) Group, biochemical and nutritional effects of rice, barley, and millet on rats are studied. The grains used in this experiment are polished ones and purchased from market. Six(6) weaning male albino rats are housed into the individual cages in each group and fed with each experimental diet and water ad libitum for 21 weeks. The composition of the experimental diets are shown in Table 1. At the end of experiment, the appearences of rats are observed and the bloods are sampled by heart puncture method following ether anesthesia for determinations of serum protein and serum cholesterol. And the livers are sampled immediately right after heart after heart puncture for determinations of liver weight, liver nitrogen, liver fat, and liver glycogen. And also liver tissues are observed histologically. The result of growth experiment is shown in Table 2 and Figure 7. The results of blood analysis are shown in Table 3 and the results of liver analysis are shown in Table 4. And the histological observations of liver tissue are shown in Figures 1, 2, 3, 4, 5, and 6. According to the above results, it could be summarized as follows; 1) The normal appearences are observed at SD Group and BD Group. Alopecia is observed at RD, RD-­BD, RD-MD, and MD groups and the wet appearences of hair are observed at RD-MD and MD groups. The color of hair is changed to yellowish white at RD, RD-MD groups. The maximum growth inhibition, is observed at MD group and the growths of RD, RD-BD, BD, and RD-MD groups are significantly lower than that of SD group. The growth of RD group is lower than those of RD-BD and BD groups, though this difference is not significant. 2) At the blood analysis, the highest serum protein content is shown at SD group and the lowest serum protein is observed at MD group. The serum cholesterol contents are not significantly different among the six(6) experimental groups. 3) The highest liver weight is observed at SD group and the lowest weight is shown at MD group. However, oppositely the highest liver weight per 100 grams of body weight at MD group and the lowest liver weight per 100 grams of body weight at SD group are observed as shown in Table 6. 4) The differences of liver nitrogen contents of RD, RB-BD, BD, RD-MD, and MD Groups are not significant except SD group showing the highest content. 5) The significant highest content of liver fat is observed at RD group and the lowest content of liver fat is shown at SD group. And no significant differences in contents of liver glycogen are observed among the six(6) experimental groups. 6) No significant abnormal histological changes of liver tissue are observed at SD, RD-BD, and BD groups. However, the fat metamorphosis at peripheral zone of liver tissue is observed at RD Group and the some histological abnormal changes are observed at RD-MD and MD groups. According to the above summaries, the followings might be estimated and recommended; 1) The BD group shows histological normality of liver tissue, improvement of liver fat and liver nitrogen, normality of appearence, and better growth compared with RD Group. This could be indicated that barley is nutritionally and biochemically better than rice as the feeding diet on rat. And it might be considered that there might be the species speciality for nutritionary evaluation of food. 2) Recently, Marshall indicated that the high consumption of carbohydrate causes fatty liver and Kondo reported that the higher consumption of rice causes the more heart disease and the shorter life span. Considering these reports, the higher consumption of rice as a main dish in our country should be considered as an important national nutritional problem. And this might be improved by supplementing with barley or other grains to rice.

• Journal of Korea Water Resources Association
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• v.46 no.6
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• pp.597-611
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• 2013

This paper presents the methodology for construction of time-area curve via the width function and thereby rational estimation of time of concentration and storage coefficient of Clark model within the framework of method of moments. To this end time-area curve is built by rescaling the grid-based width function under the assumption of pure translation and then the analytical expressions for two parameters of Clark model are proposed in terms of method of moments. The methodology in this study based on the analytical expressions mentioned before is compared with both (1) the traditional optimization method of Clark model provided by HEC-1 in which the symmetric time-area curve is used and the difference between observed and simulated hydrographs is minimized (2) and the same optimization method but replacing time-area curve with rescaled width function in respect of peak discharge and time to peak of simulated direct runoff hydrographs and their efficiency coefficient relative to the observed ones. The following points are worth of emphasizing: (1) The optimization method by HEC-1 with rescaled width function among others results in the parameters well reflecting the observed runoff hydrograph with respect to peak discharge coordinates and coefficient of efficiency; (2) For the better application of Clark model it is recommended to use the time-area curve capable of accounting for irregular drainage structure of a river basin such as rescaled width function instead of symmetric time-area curve by HEC-1; (3) Moment-based methodology with rescaled width function developed in this study also gives rise to satisfactory simulation results in terms of peak discharge coordinates and coefficient of efficiency. Especially the mean velocities estimated from this method, characterizing the translation effect of time-area curve, are well consistent with the field surveying results for the points of interest in this study; (4) It is confirmed that the moment-based methodology could be an effective tool for quantitative assessment of translation and storage effects of natural river basin; (5) The runoff hydrographs simulated by the moment-based methodology tend to be more right skewed relative to the observed ones and have lower peaks. It is inferred that this is due to consideration of only one mean velocity in the parameter estimation. Further research is required to combine the hydrodynamic heterogeneity between hillslope and channel network into the construction of time-area curve.